slowhttptest v1.5 - Application Layer DoS attack simulator released

SlowHTTPTest is a highly configurable tool that simulates some Application Layer Denial of Service attacks.

It implements most common low-bandwidth Application Layer DoS attacks, such as slowloris, Slow HTTP POST, Slow Read attack (based on TCP persist timer exploit) by draining concurrent connections pool, as well as Apache Range Header attack by causing very significant memory and CPU usage on the server.

Slowloris and Slow HTTP POST DoS attacks rely on the fact that the HTTP protocol, by design, requires requests to be completely received by the server before they are processed.

If an HTTP request is not complete, or if the transfer rate is very low, the server keeps its resources busy waiting for the rest of the data. If the server keeps too many resources busy, this creates a denial of service. This tool is sending partial HTTP requests, trying to get denial of service from target HTTP server.

Slow Read DoS attack aims the same resources as slowloris and slow POST, but instead of prolonging the request, it sends legitimate HTTP request and reads the response slowly.

Installation and usage examples

How I knocked down 30 servers using slowhttptest

Slow Read DoS attack explained

Test results of popular HTTP servers

How to protect against slow HTTP DoS attacks

Change log of Slowhttptest 1.5 -

This build includes performance improvements and ability to direct either entire or probe traffic through a web proxy.

Added ability to direct all traffic to an HTTP proxy (use -d host:port). This would most likely test the proxy server itself, rather than the target server.
Fixed two typos
Issue 13: Unable to compile — missing include files. Build fix for Arch Linux
Fix for 100% CPU usage if probe connection is too fast.
Fix for 100% CPU usage when poll keeps monitoring already closed sockets.